Slip socket



March 18, 1930. E. J. SHAFFEFQ 1,750,906

SLIP SOCKET Filed Nov. 29. 1920 2 Sheets-Sheet l March 18, 1930.

E. J SHAFFER SLIP SOCKET Filed Nov. 29. 1920 2 Sheets-Sheet 2 PatentedMar. 18, 1930 UNITED sTArEs ERNEST J. SHAFFER, OF TULSA, OKLAHOMA SLIPsocxnr Application filed Novemberfij, 1820. Serial No. 426,974;

This invention relates to slip sockets that are used for recoveringbroken or disconnected sucker rods from oil wells and the like.

The primary object of my invention, is to provide a self-contained slipsocket that will run freely in well tubing of a given diameter and catchany and all breaks that are possible of occurring in standard suckerrods designed to operate in said tubing, avoiding the necessity ofemploying different sockets for grasping, respectively, the rods andtheir boxes or couplings (the part to be caught. depending upon thelocation of the break in the rod); and eliminating the need ofinterchangeableslips for grasping rods of different diameters andcouplings of various sizes.

More specific objects of the present invention are the provision of atool of the afore said character incorporating slips that will adaptthemselves readily to rods of different diameters as well as tocouplingsof different sizes and in all instances will operate with a high degreeof efficiency; the provision of 2 slips that will adjust themselveseasily and quickly to the nature of the break; that will operate theminimum friction in the barrel; and the provision of means forpositively maintaining the slips in operative relation to each other atall times and for preventing the accidental dislodgment of a slip fromthe barrel. I v

The foregoing objects, and others which will become apparent as thisdescription proceeds, are attained in the slip socket illustrated in thedrawings accompanying andforming a part hereof and wherein Fig. 1 is acentral longitudinal section through a slip socket constructed inaccordance with my invention; Fig. 2 is a'section on the line 22 of Fig.1; Fig. 3-is a fragmentary perspective view of the set of slips; Fig. 4is a diagram showing the manner in which I cut the slips from a blank ofcircular cross section; Fig. 5 is a bottom end elevation of the slipsocket, disclosing the effect of so cutting the slips; and Figs. 6, 7and 8 show the socket executing various catches in well tubing. 7 j

The socket is composed of a'barrel 1, acap 2 that is screwed into the.upper'end of he barrel, a set of slips 3 that occupy the lower portionof the barrel, and a spring 4: interposed between the oap and slips andwhich tends to depress the latter. This combina tion, in itself, is oldand I make no claim to it except as it is affected by the improvements,residing principally in the barrel and slips, which my invention importsinto it and whereon the attainmentof the objects above enumerated aredependent.

The barrel 1, which'is preferably formed ofseamless steel tubing of hightensile strength, is shown as. cylindrical on its extee rior from end toend. The bottom of the barrel is chamfered upwardly and inwardly toprovide an inclined guide wa1l5 that surrounds what may be termed themouthof the socket. For convenience of description, the barrel may bedivided into zones at, b, c, and cl. Throughout zone a the interior ofthe barrel is threaded for the attachment of cap 2 and the wall is madesufliciently' thick to afford a substantial screw connection. Throughoutthe length of zone 6, except where it joins the threads of zone a, thebarrel is reamed out to provide thegreatest possible internal diameterwhile preserving the requisite strength of wall. Immediately below zonea, the inner wall diverges to provide a tapered shoulder.

a. Zone 0 represents a rather abrupt inward taper of the wall, whichbreaks over a shoulder 6 into a long and gradual taper that extends tothe mouth of the barrel or socket, or, in other words, throughout thelength of zone d. This portion I shall'refer to as the choke of barrel.

Here it may be explained that the barrel is of substantially the maximumdiameter that will operate practically within tubing of a size whereinthe socket is designed to work;

and that the mouth of the barrel is of a diameter approximately fivesixths of the external 7 diameter of the barrel. It isthrough theseproportions that the socket is capable of ad'- mitting couplingsof'sta'ndard size sucker The design of theslips may'bei'be'st' describedby ex-plaining briefly how'the slips rods constructed to operate in saidtubing.

the lower portion of compartment 3, or a box or coupling in compartment3 that the slips had been extended upward as far as the compression ofthe spring would allow and the upper ends of the slips had been expandedagainst the wall of the enlarged portion of the bore and could separateno further, the slips may be forced upwardly until their up perendsengage the tapered shoulder a and are rocked inward thereby so as toseparate their lower ends enough to loosen the hold on the recoveredpart, it being noted in this connection that the slips are capable ofrocking longitudinally very slightly with resepct to each other byreason of the nature of the engagement between the side edges of theslips, as illustrated in Fig. 1.

The shoulder a also serves as a stopto prevent the slips from jammingthe threads of the barrel, and to protect the threads from injuryotherwise by objects approaching them from below.

3. A slip socket comprising abarrel having a downwardly convergingfrusto-conical inner surface providing a choke", and a set'of slipsyieldingly sustained'in contracted condition within the choke of thebarrel, and having a taper corresponding substantially to that of saidfrusto-conical surface, each slip being provided at its upper end with arecess at one of its side edges, and a projecting finger at its otherside edge, the fingers of the slips engaging the recesses of theadjacent slips, and the slips being readily detachable from one anotherby a radial movement of either slip.

In testimony whereof, I hereunto affix my signature.

ERNEST J. SHAFFER.

Having thus described my invention, what 7 I claim is:

1. A slip socket designed to operate within well tubing of a givendiameter, the same comprising a barrel of substantially the maximumdiameter that will operate within said tubing, said barrel having adownwardly convergent frusto-conical inner surface providing a choke,means atthe upper end of the barrel to permit the same to be loweredinto a well, and a set of slips yieldingly sustained in contractedcondition within the.

choke of the barrel, and having a taper corresponding substantially tothat of the inner surface of the barrel, the upper portion of the barrelhaving a cylindrical inner surface to permit the slips to recede intothe same, and the outer surface of each slip be ing so shaped as to bearonly adjacent its edges upon the frusto-conical surface of the barrelwhen the slips are in contracted condition.

2. A slip socket comprising a barrel having a lower downwardly covergingfrustoconical inner surface providing a choke, the inner surface of theintermediate portion of the barrel being cylindrical in shape, and theupper end portion of the barrel being thickened and provided withinternal screw threads, a screw threaded cap engaging said screw threadsand removable from the barrel, the inner surface of the barrel betweenthe threads and cylindrical surface being gradually tapered upwardlyand'inwardly to provide an annular cam surface, and a set of slipsyieldingly sustained in contracted condition within the choke ofthebarrel,

each slip being provided at its upper end I portion with an inclinedsurface complementary to said cam surface, and adapted to engage thelatter for rocking the slips to release the same from any tool which ithas

